Various forms of chain tensioning devices have been heretofore designed for use in conjunction with motorcycle chains as well as drive chains found in other environments. When a chain tensioner is used on a motorcycle equipped with swing arm suspension for the rear wheel of the motorcycle, it is imperative that the chain tightener be located closely forward of the lower forward quadrant of the driven sprocket carried by the rear wheel of the motorcycle. In this manner, minimum shifting of the chain relative to the mounting portion on the adjacent swing arm for the chain tightener in response to oscillation of the swing arm is experienced and the chain tightener may more readily effect more even tension on the chain even when the motorcycle is traveling at high speeds over rough terrain.
While many of the previously designed chain tensioners are operative to perform the desired chain tensioning operation under other than severe conditions, most previously provided chain tensioners do not perform well under adverse conditions.
Examples of various forms of previously patented chain tensioners are disclosed in U.S. Pat. Nos. 3,136,170, 3,198,025, 3,673,884, 3,834,246, 3,834,477 and 3,838,606.